diff --git a/aio/content/guide/testing.md b/aio/content/guide/testing.md
index 0c70b2fa63..7bb81bc831 100644
--- a/aio/content/guide/testing.md
+++ b/aio/content/guide/testing.md
@@ -61,7 +61,7 @@ You can fine-tune many options by editing the `karma.conf.js` and
 the `test.ts` files in the `src/` folder.
 
 The `karma.conf.js` file is a partial karma configuration file.
-The CLI constructs the full runtime configuration in memory,based on application structure specified in the `angular.json` file, supplemented by `karma.conf.js`.
+The CLI constructs the full runtime configuration in memory, based on application structure specified in the `angular.json` file, supplemented by `karma.conf.js`.
 
 Search the web for more details about Jasmine and karma configuration.